There is substantial evidence that traditional instructional methods have not been successful in helping students to restructure their commonsense conceptions and learn the conceptual structures of scientific theories. This paper argues that the nature of the changes and the kinds of reasoning required in a major conceptual restructuring of a representation of a domain are fundamentally the same in the discovery and in the learning processes. Understanding conceptual change as it occurs in science and in (...) learning science will require the development of a common cognitive model of conceptual change. The historical construction of an inertial representation of motion is examined and the potential instructional implications of the case are explored. (shrink)

This volume explores questions about conceptual change from both scientific and philosophical viewpoints by analyzing the recent history of evolutionary developmental biology. It features revised papers that originated from the workshop "Conceptual Change in Biological Science: Evolutionary Developmental Biology, 1981-2011" held at the Max Planck Institute for the History of Science in Berlin in July 2010. The Preface has been written by Ron Amundson. In these papers, philosophers and biologists compare and contrast key concepts (...) in evolutionary developmental biology and their development since the original, seminal Dahlem conference on evolution and development held in Berlin in 1981. Many of the original scientific participants from the 1981 conference are also contributors to this new volume and, in conjunction with other expert biologists and philosophers specializing on these topics, provide an authoritative, comprehensive view on the subject. Taken together, the papers supply novel perspectives on how and why the conceptual landscape has shifted and stabilized in particular ways, yielding insights into the dynamic epistemic changes that have occurred over the past three decades. This volume will appeal to philosophers of biology studying conceptual change, evolutionary developmental biologists focused on comprehending the genesis of their field and evaluating its future directions, and historians of biology examining this period when the intersection of evolution and development rose again to prominence in biological science. (shrink)

Many of the experiments that produced the empirical basis of quantum mechanics relied on classical assumptions that contradicted quantum mechanics. Historically this did not cause practical problems, as classical mechanics was used mostly when it did not happen to diverge too much from quantum mechanics in the quantitative sense. That fortunate circumstances, however, did not alleviate the conceptual problems involved in understanding the classical experimental reasoning in quantum-mechanical terms. In general, this type of difficulty can be expected when a (...) coherent scientific tradition undergoes a theoretical upheaval. The problem may be circumvented through the use of phenomenological theory in experimentation during the period of theoretical instability. (shrink)

This thesis focuses on models of conceptual change in science and philosophy. In particular, I developed a new bootstrapping methodology for studying conceptual change, centered around the formalization of several popular models of conceptual change and the collective assessment of their improved formal versions via nine evaluative dimensions. Among the models of conceptual change treated in the thesis are Carnap’s explication, Lakatos’ concept-stretching, Toulmin’s conceptual populations, Waismann’s open texture, Mark Wilson’s (...) patches and facades, Sneed’s structuralism, and Paul Thagard’s conceptual revolutions. -/- In order to analyze and compare the conception of conceptual change provided by these different models, I rely on several historical reconstructions of episodes of scientific conceptual change. The historical episodes of scientific change that figure in this work include the emergence of the morphological concept of fish in biological taxonomies, the development of scientific conceptions of temperature, the Church-Turing thesis and related axiomatizations of effective calculability, the history of the concept of polyhedron in 17th and 18th century mathematics, Hamilton’s invention of the quaternions, the history of the pre-abstract group concepts in 18th and 19th century mathematics, the expansion of Newtonian mechanics to viscous fluids forces phenomena, and the chemical revolution. I will also present five different formal and informal improvements of four specific models of conceptual change. I will first present two different improvements of Carnapian explication, a formal and an informal one. My informal improvement of Carnapian explication will consist of a more fine-grained version of the procedure that adds an intermediate, third step to the two steps of Carnapian explication. I will show how this novel three-step version of explication is more suitable than its traditional two-step relative to handle complex cases of explications. My second, formal improvement of Carnapian explication will be a full explication of the concept of explication itself within the theory of conceptual spaces. By virtue of this formal improvement, the whole procedure of explication together with its application procedures and its pragmatic desiderata will be reconceptualized as a precise procedure involving topological and geometrical constraints inside the theory of conceptual spaces. My third improved model of conceptual change will consist of a formal explication of Darwinian models of conceptual change that will make vast use of Godfrey-Smith’s population-based Darwinism for targeting explicitly mathematical conceptual change. My fourth improvement will be dedicated instead to Wilson’s indeterminate model of conceptual change. I will show how Wilson’s very informal framework can be explicated within a modified version of the structuralist model-theoretic reconstructions of scientific theories. Finally, the fifth improved model of conceptual change will be a belief-revision-like logical framework that reconstructs Thagard’s model of conceptual revolution as specific revision and contraction operations that work on conceptual structures. -/- At the end of this work, a general conception of conceptual change in science and philosophy emerges, thanks to the combined action of the three layers of my methodology. This conception takes conceptual change to be a multi-faceted phenomenon centered around the dynamics of groups of concepts. According to this conception, concepts are best reconstructed as plastic and inter-subjective entities equipped with a non-trivial internal structure and subject to a certain degree of localized holism. Furthermore, conceptual dynamics can be judged from a weakly normative perspective, bound to be dependent on shared values and goals. Conceptual change is then best understood, according to this conception, as a ubiquitous phenomenon underlying all of our intellectual activities, from science to ordinary linguistic practices. As such, conceptual change does not pose any particular problem to value-laden notions of scientific progress, objectivity, and realism. At the same time, this conception prompts all our concept-driven intellectual activities, including philosophical and metaphilosophical reflections, to take into serious consideration the phenomenon of conceptual change. An important consequence of this conception, and of the analysis that generated it, is in fact that an adequate understanding of the dynamics of philosophical concepts is a prerequisite for analytic philosophy to develop a realistic and non-idealized depiction of itself and its activities. (shrink)

Biology is the study of life, psychology is the study of mind, and medicine is the investigation of the causes and treatments of disease. This chapter describes how the central concepts of life, mind, and disease have undergone fundamental changes in the past 150 years or so. There has been a progression from theological, to qualitative, to mechanistic explanations of the nature of life, mind and disease. This progression has involved both theoretical change, as new theories with greater explanatory (...) power replaced older ones, and emotional change as the new theories brought reorientation of attitudes toward the nature of life, mind, and disease. After a brief comparison of theological, qualitative, and mechanistic explanations, I will describe how shifts from one kind of explanation to another have carried with them dramatic kinds of conceptual change in the key concepts in the life sciences. Three generalizations follow about the nature of conceptual change in the history of science: there has been a shift from conceptualizations in terms of simple properties to ones in terms of complex relations; conceptual change is theory change; and conceptual change is often emotional as well as cognitive. The contention that historical development proceeds in three stages originated with the nineteenth-century French philosophers, Auguste Comte, who claimed that November 9, 2006 human intellectual development progresses from a theological to a “metaphysical” stage to a “positive” (scientific) stage (Comte, 1988). The stages I have in mind are different from Comte’s, so let me say what they involve. By the theological stage I mean systems of thought in which the primary explanatory entities are supernatural ones beyond the reach of science, such as gods, devils, angels, spirits, and souls. For example, the concept of fire was initially theological, as in the Greek myth of Prometheus receiving fire from the gods.. (shrink)

I present philosophical reflections arising from a study of laboratory measurement methods in quantum physics. More specifically, I investigate three major methods of measuring kinetic energy, from the period during which quantum physics was developed and came to be widely accepted: magnetic deflection, electrostatic retardation, and material retardation. The historical material serves as a provocative focus at which many broader philosophical topics come together: the empirical testing of theories, the universal validity of physical laws, the interaction between theoretical and experimental (...) traditions, incommensurability, meaning and definition, realism and instrumentalism, the process of scientific change, and the unity of science. ;I begin the discussion by noting that the measurement methods in question were based on classical theory. Chapter 1 asks how the classical reasoning in measurements can be interpreted in quantum-mechanical terms, and concludes that only a "surface interpretation" is possible, since the classical methods involve many assumptions that conflict with quantum mechanics. Chapter 2 attempts to give a quantitative assessment of the inaccuracies that might result from using the "incorrect" classical theory in the design of measurement methods. Chapter 3 asks how we can know whether a measurement method is reliable, and investigates how different methods of measuring the same quantity can ground each other; this mutual grounding is also seen as a process of concept-formation. Chapter 4 argues that the customary quantum theories of measurement do not describe actual measurements well, and originate from an overly literal interpretation of the operator formalism of quantum mechanics. Chapter 5 examines how the classically reasoned measurement methods were incorporated into quantum physics; that history suggests a model of scientific development which can introduce fundamental changes while preserving much continuity with the old tradition. Chapter 6 develops a philosophical framework which allows a synthetic view of the concrete results presented in the earlier chapters: my work is an attempt to establish "conceptual coherence," creating and clarifying noncontradictory connections among the various conceptual activities that make up quantum physics. (shrink)

I once wrote to Imré Lakatos that if he had not already established himself as an accomplished philosopher and provocateur, he could have made a successful career as a Hollywood script writer. I had in mind, at that time, a beautifully written paper he had constructed by pasting together the cuttings from other papers. I had forgotten that his reputation as a dramatist was already established, with the production of his Proofs and Refutations [9]. For that work, it seems to (...) me, is simply a play within a play. The main character, whose part is written in the footnotes, delivers a monologue which is a commentary on the drama, between teacher and students, that occupies center stage. This main character is not named in the play, so for ease of reference I shall call him “Imré”. What Imré points out is that the drama on center stage imitates life, in showing us the essential features of the methodology by virtue of which mathematical science grows. (shrink)

Computational modeling of sketch understanding is interesting both scientifically and for creating systems that interact with people more naturally. Scientifically, understanding sketches requires modeling aspects of visual processing, spatial representations, and conceptual knowledge in an integrated way. Software that can understand sketches is starting to be used in classrooms, and it could have a potentially revolutionary impact as the models and technologies become more advanced. This paper looks at one such effort, Sketch Worksheets, which have been used in multiple (...) classroom experiments already, with students ranging from elementary school to college. Sketch Worksheets are a software equivalent of pencil and paper worksheets commonly found in classrooms, but they provide on-the-spot feedback based on what students draw. They are built on the CogSketch platform, which provides qualitative visual and spatial representations and analogical processing based on computational models of human cognition. This paper explores three issues. First, we examine how research from cognitive science and artificial intelligence, combined with the constraints of creating new kinds of educational software, led to the representations and processing in CogSketch. Second, we examine how these capabilities have been used in Sketch Worksheets, drawing upon experiments with fifth-grade students in biology and college students in engineering design and in geoscience. Finally, we examine some open issues in sketch understanding that need to be addressed to better model high-level aspects of vision, and for sketch understanding systems to reach their full potential for supporting education. (shrink)

Scientific revolution is a widely known concept. But does revolution really occur in science? Change through revolution means that present thinking does not retain anything from the past, because everything is thrown away due to the revolution. Does this pattern of change really correspond to the history of science? There is another pattern which is called evolution. This writing will show that process of evolution rather than revolution presents the real situation of scientific change. According (...) to this concept, science grows as an organic species grows in certain environment. An organism is different from its every former stage, yet it remains the same organism throughout its life. In the same way, we will find both change and continuity in scientific growth. (shrink)

In recent years, researchers within science education have started to consider the impact of narrative upon teaching and learning in science. This article investigates the possibilities of interactive fiction as a means by which students can be provided with feedback on their understanding in science, and explores the mechanisms which might allow learning from this. Through a review of literature around the use of narrative in science education, we have produced a list of recommendations that might (...) guide the development of interactive fiction within science education. These recommendations are tested through a small-scale study in which an interactive fiction book was written around Newton’s laws, and then tested with 27, 16- and 17-year-old chemistry students, eight of whom also study post-compulsory physics. The interactive fiction developed is based upon the well-established Force Concept Inventory and this allowed the analysis of the progression of student understanding. We found that, upon reading the book, there was a significant positive effect size on the understanding of students who do not study advanced physics. The gains for those who do study post-compulsory physics were not statistically significant. The participants’ report of enjoyment is also discussed. (shrink)

I focus on the concept of the receptive field of a sensory neuron, taking it as a prominent case to address conceptual change in the history of neuroscience. I argue for an interpretation of its ro...

The articles comprising this dissertation concern classification and concept formation in the social and behavioral sciences. In particular, the emphasis in the study is on the philosophical analysis of interdisciplinary settings created by the recent intellectual developments on the interfaces between the social sciences, psychology, and neuroscience. The need for a systematic examination of the problems of conceptual coordination and integration across disciplinary boundaries is illustrated by focusing on phenomena whose satisfactory explanation requires drawing together the theoretical resources from (...) a variety of disciplines. In philosophy, questions regarding the nature of scientific concepts have often been framed in terms of theories of natural kinds. For this reason, analysis of the notion of natural kind as well as examination of how theories of natural kinds should be connected to recent philosophical accounts of scientific explanation and mechanisms form the core of the study. Building on contemporary discussions on these topics in the philosophy of biology, the philosophy of cognitive science, and the philosophy of the social sciences, the articles develop a mechanistic theory of natural kinds in the social and behavioral sciences, and scrutinize its applicability and usefulness as a theory of conceptual change in interdisciplinary settings. The study suggests that, although the mechanistic theory cannot account for the functioning of the whole range of scientific concepts, interweaving biological, cognitive, and social mechanisms in the manner suggested by the mechanistic theory offers a naturalistic and non-reductionist basis for conceptualizing epistemic coordination across disciplinary boundaries. (shrink)

The theoretical status of ‘niche construction’ in evolution is intensely debated. Here we substantiate the reasons for different interpretations. We consider two concepts of niche construction brought to bear on evolutionary theory; one that emphasizes how niche construction contributes to selection and another that emphasizes how it contributes to development and inheritance. We explain the rationale for claims that selective and developmental niche construction motivate conceptual change in evolutionary biology and the logic of those who reject these claims. (...) Our analysis shows how the contention arises from alternative assumptions regarding the causal independence of the processes that generate variation, differential fitness and inheritance. (shrink)

I argue that the Conceptual Ethics and Conceptual Engineering framework, in its pragmatist version as recently defended by Thomasson, provides a means of articulating and defending the conventionalist interpretation of projects of conceptual extension (e.g. the extended mind, the extended phenotype) in biology and psychology. This promises to be illuminating in both directions: it helps to make sense of, and provides an explicit methodology for, pragmatic conceptual extension in science, while offering further evidence for the (...) value and fruitfulness of the Conceptual Ethics/Engineering framework itself, in particular with respect to conceptual change within science, which has thus-far received little attention in the literature on Conceptual Ethics/Engineering. (shrink)

This article outlines how conceptual spaces theory applies to modeling changes of scientific frameworks when these are treated as spatial structures rather than as linguistic entities. The theory is briefly introduced and five types of changes are presented. It is then contrasted with Michael Friedman’s neo-Kantian account that seeks to render Kuhn’s “paradigm shift” as a communicatively rational historical event of conceptual development in the sciences. Like Friedman, we refer to the transition from Newtonian to relativistic mechanics as (...) an example of “deep conceptual change.” But we take the communicative rationality of radical conceptual change to be available prior to the philosophical meta-paradigms that Friedman deems indispensable for this purpose. (shrink)

Lakatos’ (Lakatos, 1976) model of mathematical conceptual change has been criticized for neglecting the diversity of dynamics exhibited by mathematical concepts. In this work, I will propose a pluralist approach to mathematical change that re-conceptualizes Lakatos’ model of proofs and refutations as an ideal dynamic that mathematical concepts can exhibit to different degrees with respect to multiple dimensions. Drawing inspiration from Godfrey-Smith’s (Godfrey-Smith, 2009) population-based Darwinism, my proposal will be structured around the notion of a conceptual (...) population, the opposition between Lakatosian and Euclidean populations, and the spatial tools of the Lakatosian space. I will show how my approach is able to account for the variety of dynamics exhibited by mathematical concepts with the help of three case studies. (shrink)

In this book, David Stump traces alternative conceptions of the a priori in the philosophy of science and defends a unique position in the current debates over conceptual change and the constitutive elements in science. Stump emphasizes the unique epistemological status of the constitutive elements of scientific theories, constitutive elements being the necessary preconditions that must be assumed in order to conduct a particular scientific inquiry. These constitutive elements, such as logic, mathematics, and even some fundamental (...) laws of nature, were once taken to be a priori knowledge but can change, thus leading to a dynamic or relative a priori. Stump critically examines developments in thinking about constitutive elements in science as a priori knowledge, from Kant’s fixed and absolute a priori to Quine’s holistic empiricism. By examining the relationship between conceptual change and the epistemological status of constitutive elements in science, Stump puts forward an argument that scientific revolutions can be explained and relativism can be avoided without resorting to universals or absolutes. (shrink)

This volume offers one of the first systematic analyses of the rise of modern social science. Contrary to the standard accounts of various social science disciplines, the essays in this volume demonstrate that modern social science actually emerged during the critical period between 1750 and 1850. It is shown that the social sciences were a crucial element in the conceptual and epistemic revolution, which parallelled and partly underpinned the political and economic transformations of the modern world. (...) From a consistently comparative perspective, a group of internationally leading scholars takes up fundamental issues such as the role of the Enlightenment and the French Revolution in the shaping of the social sciences, the changing relationships between political theory and moral discourse, the profound transformation of philosophy, and the constitution of political economy and statistics. (shrink)

Maurits Cornelis Escher’s 1938 lithograph, Cycle, illustrates what mathematical physicist Roger Penrose calls ‘impossible objects’. The illusion of three-dimensionality, the innovative use of tessellation, and the incorporation of traditionally figurative elements induce the viewer to perceive the lithographic print as depicting a visually plausible reality built on the deconstructive metamorphosis of man into cube. It is Escher’s ability to paradoxically combine the radical oppositions of man and cube, landscape and geometric abstraction into an apparently harmonious composition where shapes repeat with (...) subtle variation and almost imperceptibly transition into radically different shapes that I want to use as a visual paradigm for conceptualizing the shifts in human consciousness in the digital age. Roger Penrose, path-breaking theorist of consciousness as a physical but non-computational process, was inspired by and inspired Escher. Penrose’s provisional concepts of consciousness, time and space can be visually compared to Escher’s earlier man-cube renderings, where each of these individual design elements allows the transition to another shape. In other words, Penrose’s theories, like Escher’s design concepts, illustrate a moment of transition in consciousness theory. As in Escher’s Cycle, the individual elements are being continually redefined, reshaped and revealed. Each may be a unique distortion of the previous, but this does not mean that it is disconnected or independent of the final outcome. These distortions are transitional elements that lead us visually to the other side of the composition. Radical transformations and developing connectedness in the boundaries between art, technology and science function like the individual elements in Escher’s Cycle. As we try to define the shifts in human consciousness occurring in the digital age, visually speaking, we are focusing on only one element right in the middle of an Escher metamorphosis, unable to see exactly how this element will be part of the completed design. This thought can be both frightening and liberating: frightening because we humans are used to relying on boundaries and predictable outcomes to feel a sense of control, liberating because anything and everything is possible and the changes will occur naturally as part of the transition. If Escher teaches us anything, it is that each piece in the meta-morphosis is needed to complete the big picture. (shrink)

ArgumentThis paper studies the evolution of mathematics teaching in France and Germany from 1900 to about 1980. These two countries were leading in the processes of international modernization. We investigate the similarities and differences during the various periods, which showed to constitute significant time units and this in a remarkably parallel manner for the two countries. We argue that the processes of reform concerning the teaching of this major school subject are not understandable from within mathematics education or even within (...) the school system. Rather, the evolution of the processes of reform prove to be intimately tied to changing conceptions of modernity according to respective social and cultural values and to changing epistemological conceptions of mathematics. It is particularly novel that we show the key impact of the changing social status of primary schooling for these modernization processes. (shrink)

The theory of concepts advanced in the dissertation aims at accounting for a) how a concept makes successful practice possible, and b) how a scientific concept can be subject to rational change in the course of history. Traditional accounts in the philosophy of science have usually studied concepts in terms only of their reference; their concern is to establish a stability of reference in order to address the incommensurability problem. My discussion, in contrast, suggests that each scientific concept (...) consists of three components of content: 1) reference, 2) inferential role, and 3) the epistemic goal pursued with the concept's use. I argue that in the course of history a concept can change in any of these three components, and that change in one component—including change of reference—can be accounted for as being rational relative to other components, in particular a concept's epistemic goal.This semantic framework is applied to two cases from the history of biology: the homology concept as used in 19th and 20th century biology, and the gene concept as used in different parts of the 20th century. The homology case study argues that the advent of Darwinian evolutionary theory, despite introducing a new definition of homology, did not bring about a new homology concept (distinct from the pre-Darwinian concept) in the 19th century. Nowadays, however, distinct homology concepts are used in systematics/evolutionary biology, in evolutionary developmental biology, and in molecular biology. The emergence of these different homology concepts is explained as occurring in a rational fashion. The gene case study argues that conceptual progress occurred with the transition from the classical to the molecular gene concept, despite a change in reference. In the last two decades, change occurred internal to the molecular gene concept, so that nowadays this concept's usage and reference varies from context to context. I argue that this situation emerged rationally and that the current variation in usage and reference is conducive to biological practice.The dissertation uses ideas and methodological tools from the philosophy of mind and language, the philosophy of science, the history of science, and the psychology of concepts. (shrink)

Analogical inferences are an important consequence of the way semantic knowledge is represented, that is, with relations as explicit structures that can take arguments. We review evidence that this feature of semantic cognition successfully predicts how quickly and broadly children's concepts change with experience and show that Rogers & McClelland's (R&M's) parallel distributed processing (PDP) model fails to simulate these cognitive changes due to its handling of relational information.

The theory of concepts advanced in the dissertation aims at accounting for a) how a concept makes successful practice possible, and b) how a scientific concept can be subject to rational change in the course of history. Traditional accounts in the philosophy of science have usually studied concepts in terms only of their reference; their concern is to establish a stability of reference in order to address the incommensurability problem. My discussion, in contrast, suggests that each scientific concept (...) consists of three components of content: 1) reference, 2) inferential role, and 3) the epistemic goal pursued with the concept's use. I argue that in the course of history a concept can change in any of these three components, and that change in one component—including change of reference—can be accounted for as being rational relative to other components, in particular a concept's epistemic goal. This semantic framework is applied to two cases from the history of biology: the homology concept as used in 19th and 20th century biology, and the gene concept as used in different parts of the 20th century. The homology case study argues that the advent of Darwinian evolutionary theory, despite introducing a new definition of homology, did not bring about a new homology concept (distinct from the pre-Darwinian concept) in the 19th century. Nowadays, however, distinct homology concepts are used in systematics/evolutionary biology, in evolutionary developmental biology, and in molecular biology. The emergence of these different homology concepts is explained as occurring in a rational fashion. The gene case study argues that conceptual progress occurred with the transition from the classical to the molecular gene concept, despite a change in reference. In the last two decades, change occurred internal to the molecular gene concept, so that nowadays this concept's usage and reference varies from context to context. I argue that this situation emerged rationally and that the current variation in usage and reference is conducive to biological practice. The dissertation uses ideas and methodological tools from the philosophy of mind and language, the philosophy of science, the history of science, and the psychology of concepts. (shrink)

Professor Grosholz packs a lot into her interesting and suggestive paper “Formal Unities and Real Individuals” (Grosholz 1990b). In the limited space available I can comment briefly on its several parts, or direct more substantive comments at a single issue. I will opt for the latter; specifically, I want to address her critique of mathematical structuralism, as found especially in the writings of Michael Resnik.I begin with a brief, hence necessarily caricatured, summary of Resnik’s influential view. According to structuralism, the (...) subject matter of a mathematical theory is a given pattern, or structure, and the objects of the theory are intrinsically unstructured points, or positions, within that pattern. Mathematical objects thus have no identity, and no intrinsic features, outside of the patterns in which they occur. Hence, they cannot be given in isolation but only in their role within an antecedently given pattern, and are distinguishable from one another only in virtue of the relations they bear to one another in the pattern (see, e.g., Resnik (1981)). (shrink)

I address Grosholz's critique of Resnik's mathematical structuralism and suggest that although Resnik's structuralism is not without its difficulties it survives Grosholz's attacks.

In this paper we attempt to identify which peer collaboration characteristics may be accountable for conceptual change through interaction. We focus on different socio‐cognitive aspects of the peer dialog and relate these with learning gains on the dyadic as well as the individual level. The scientific topic that was used for this study concerns natural selection, a topic for which students’ intuitive conceptions have been shown to be particularly robust. Learning tasks were designed according to the socio‐cognitive conflict (...) instructional paradigm. After receiving a short instructional intervention on natural selection, paired students were asked to collaboratively construct explanations for certain evolutionary phenomena while engaging in dialectical argumentation. Two quantitative coding schemes were developed, each with a different granularity. The first assessed discrete dialog moves that pertained to dialectical argumentation and to consensual explanation development. The second scheme characterized the dialog as a whole on a number of socio‐cognitive dimensions. Results from analyses on the dyadic as well as the individual level revealed that the engagement in dialectical argumentation predicted conceptual learning gains, whereas consensual explanation development did not. These findings open up new venues for research on the mechanisms of learning in and from peer collaboration. (shrink)